Large blood vessel stretch in lumbar spine through anterior surgical approach: An experimental study in adult goat

Ureteral injury following anterior thoracolumbar spinal instrumented fusion for adolescent idiopathic scoliosis: a case report with CT angiography analysis of surgically relevant anatomy

PURPOSE

To report a rare ureteral injury following anterior spinal fusion for adolescent idiopathic scoliosis (AIS) that resulted in complete nephrectomy and to delineate the anatomical relationship between the proximal ureter and the anterior lumbar spine based on CT angiography (CTA).

METHODS

Thoracolumbar spine CTAs of children with AIS were reviewed. We measured the following relationships to the ureters: lateral-most aspect of vertebral body, anterior psoas at intervertebral disc/vertebral body levels, and lateral psoas at vertebral body level. Spine level at which the renal arteries originated from the aorta was identified. Distance from origin to corresponding vertebral body/intervertebral disc also was measured.

RESULTS

Forty-one girls and seven boys (mean age 12 years, range 7-18) were analyzed. Scoliosis lumbar convexity was left 94% and right 6%. From L1 to L4, ureter was identified within 1-2 cm of vertebral body. Distance between ureter and vertebral body and ureter and anterior psoas at intervertebral disc/vertebral body levels was less on left vs. right from L1 to L4 (p < 0.0001). Distance between ureter and lateral psoas was less on left vs. right from L1 to L2 (p = 0.0205; p = 0.0132) and greater on left vs. right from L3 to L4 (p = 0.0022; p = 0.0076). Renal artery originated at L1/L2 in > 50%. There was no difference in distance from renal artery origin to vertebral body/intervertebral disc (p = 0.4764).

CONCLUSION

Ureteral injury is a potentially morbid complication of anterior spine surgery. Injury can occur secondary to disrupted blood supply and mechanical tissue damage. Surgeons must clearly understand the juxta-spinal anatomy to limit dissection and modify retraction to reduce risk.

LEVEL OF EVIDENCE

Level IV.

Magnetic Resonance Imaging Study of Oblique Corridor and Trajectory to L1-L5 Intervertebral Disks in Lateral Position

OBJECTIVE

This study investigated the retroperitoneal oblique corridor and trajectory of L1-L5 as the lateral surgical access to the intervertebral disks in the Chinese population and detected the potential relationship between the corridor or trajectory and vertebral parameters, including disk axis, psoas muscle, and retroperitoneal vessel.

METHODS

Seventy magnetic resonance imaging studies performed from January 2017 to January 2019 were investigated. The oblique corridor was defined as the distance between the left lateral border of the retroperitoneal vessel and the anterior border of psoas. The trajectory was defined as the distance between the retroperitoneal vessel and lumbar plexus.

RESULTS

The oblique corridor analysis to L1-L5 disks have the following mean distances: L1-2 13.36 mm, L2-3 13.36 mm, L3-4 12.37 mm, and L4-5 10.36 mm. There was no difference in the L1-L5 corridor between genders. And the position of retroperitoneal vessel was negatively correlated with the corridor width. The trajectory measurements to L1-L5 disks have the following mean distances: L1-2 27.44 mm, L2-3 30.86 mm, L3-4 30.73 mm, and L4-5 24.36 mm. Moreover, the vertebral parameters, including the disk axis and psoas muscle, were positively correlated with the trajectory width. Otherwise, the position of retroperitoneal vessel was negatively correlated with the trajectory width.

CONCLUSIONS

Compared with previous studies, the safe surgical area of the Chinese is generally smaller than that of Caucasian. The position of the retroperitoneal vessel is the vital potential to limit the corridor and trajectory. Preoperative assessment of vertebral parameters, especially vascular structure, is essential for planning surgical process.

Imaging Anatomical Research on the Operative Windows of Oblique Lumbar Interbody Fusion

To provide applied anatomical evidence of the preoperative assessment of oblique lumbar interbody fusion (OLIF), the anatomical parameters of the OLIF operative window were observed through computed tomography angiography (CTA). We selected imaging data from 60 adults (30 males, 30 females) who underwent abdominal CTA and T12-S1 vertebral computed tomography (CT) with three-dimensional reconstruction. The OLIF operative windows at the L1-2, L2-3, L3-4, L4-5 and L5-S1 levels were as follows: the vascular window, bare window, psoas major window, ideal operative window, and actual operative window. Each level's actual operative window was statistically analyzed based on an actual operative window of <1 cm and ≥1 cm. The vascular window was largest at L4-5 (1.72 ± 0.58 cm). The bare window was largest at L5-S1 (1.59 ± 0.93 cm) and smallest at L3-4 (1.37 ± 0.51 cm). The psoas major window was largest at L3-4 (1.14 ± 0.35 cm) and smallest at L1-2 (0.41 ± 0.34 cm). The ideal operative window was largest at L4-5 (3.74 ± 0.36 cm) and smallest at L1-2 (3.23 ± 0.30 cm). The actual operative window was largest at L3-4, followed by L2-3, L4-5, L1-2, and L5-S1, which were 2.51 ± 0.56 cm, 2.28 ± 0.54 cm, 2.01 ± 0.74 cm, 1.80 ± 0.45 cm and 1.59 ± 0.93 cm, respectively (P = 0.000), and the percentages of the actual surgical window were 69%, 66%, 53%, 56% and 43%, respectively. The actual surgical window was <1 cm in 2 cases at L1-2 (3.3%), 4 cases at L4-5 (6.7%), and 17 cases at L5-S1 (28.3%) (11 males and 6 females). The regional anatomy of each level related to OLIF has its own peculiarities, and not all levels are suitable for OLIF. Before OLIF surgery, surgeons should analyze the imaging anatomy and select the appropriate surgical procedures.